Refractory gun mix

Abstract

A refractory gun mix of improved properties, particularly low rebound, wide water range, and good adherence when gunned onto hot surfaces, used a bonding system of from 1 to 5% sodium silicate, 0.3 to 3% gypsum, and 0 to 5% bentonite, the percentages being based on the total weight of the composition. The gun mix may contain other materials, for example pulverized pitch.

I claim: 
     
       1. A refractory gun mix consisting essentially of from 1 to 5% sodium silicate, from 0.3 to 3% gypsum, and from 0 to 5% bentonite, the balance being refractory aggregate, all percentages being by weight and based on the total weight of the composition. 
     
     
       2. Gun mix according to claim 1 wherein the refractory aggregate is basic refractory aggregate. 
     
     
       3. Gun mix according to claim 2 wherein the refractory aggregate is a magnesia-containing material. 
     
     
       4. Gun mix according to claim 3 wherein the refractory aggregate is prereacted magnesia-chrome grain. 
     
     
       5. Gun mix according to claim 1, 2, 3, or 4 wherein the composition contains about 2% sodium silicate, 1% gypsum, and 1.5% bentonite. 
     
     
       6. Gun mix according to claim 5 wherein the sodium silicate has an SiO 2  :Na 2  O ratio of about 2.